Head and body length is 175-310 mm and tail length is 250-440
mm. Weights range from 225-900 g. Some, such as in the hairy-faced group, have long hairs
around the face and head. Some have mustaches while others have
short white hairs which cover the entire area around the mouth.
Coloration varies greatly among the species as do markings.

Preferred habitats are tropical forests, open woodlands, and
secondary growth. They are diurnal and arboreal, traveling
through the trees with rather quick, jerky movements. Social
group structures and sizes vary amongst species as do the physical
traits. Some species have been found cohabitating, and as a
result these mixed troops are able to use information to find
the best food sources.

In C. jacchus, breeding occurs seasonally. Usually 2
offspring are delivered after a gestation period of around 140
days after an estrous cycle of about 15 days. In females sexual
maturity is reached at 18 months and 24 months for males. The
father, as in other marmosets,
helps with the delivery of its babies, receiving and washing
them. When born, babies have very short hair. They cling very
tightly to either parent, and will be transferred to the mother
during feeding time. At 21 days, the youngsters begin to explore
a bit, but ride on their parents backs until the age of 6-7
weeks.

C. jacchus is found on the Brazilian coast: in Piaui, Ceara, and the Pernambuco Provinces.